Hybrid electric vehicles are known, which are equipped with a power-train, comprising a thermal engine with small engine displacement, and a dual-dry-clutch transmission (DDCT) integrating an electrical machine operating as electric motor/generator, which can be activated, among other operations, for starting the thermal engine in lieu of the starting motor.
The hybrid power-train is, for example, able to perform the following functions: engine stop and start through the electric driving motor; launch and creep in electrical mode; economy gear shifting; regenerative braking; and electric torque boost.
These electric vehicles are equipped for their operation with a high-voltage electric battery (which supplies, for example, a rated voltage of 240 V), the so-called <<traction battery>>, which can also be recharged directly from the power mains, and with a low-voltage electric battery (which supplies, for example, a rated voltage of 12 V), the so-called <<service battery>>, which is recharged starting from the traction battery. In particular, the service battery is designed to supply a wide range of electrical loads of the vehicle, such as, for example, the lights, the air-conditioning assembly, or other low-power actuator assemblies. The aforesaid electric vehicles are moreover equipped with an electrical power drive, including inter alia: a high-voltage battery-charger for charging the traction battery starting from the power mains, made up of a power-factor-corrector (PFC) stage, cascaded to which is a voltage-reduction (<<buck>> or <<step-down>>) stage; and a low-voltage battery-charger for charging the service battery starting from the traction battery, constituted basically by a DC/DC converter device.
In particular, the DC/DC converter device, generally known in the technical field as a “power transfer device”, replaces the function traditionally performed by the alternator in charging the service battery and can control the recharging profile, supplying appropriate output voltages and currents (and hence powers).
The possibility is known, in this regard, of implementing appropriate algorithms for controlling a power converter (for example, the aforesaid DC/DC converter device) in a digital way, with the aid of a microprocessor or microcontroller (or similar computing and processing tool), which has been appropriately programmed.
In the example of application illustrated previously, the vehicle can, for example, be equipped with a microprocessor or microcontroller, designed to implement the strategies for control both of the high-voltage battery-charger and of the low-voltage battery-charger.
The use of a digital control system, albeit advantageous from many points of view, amongst which that of enabling a wide configurability and programmability of the control action, has the drawback of involving production costs that may even be high, linked mainly to the use of a microprocessor or microcontroller; these costs are, in particular, the higher, the higher the computing and processing power required from the same microprocessor or microcontroller.
In this regard, in the case of switching power-converter devices, the need to adopt high switching frequencies so as to reduce (in a known way) the dimensions of the analog circuit components used, comes up against the consequent need to use so-called <<high-range>> microprocessors or microcontrollers, i.e., ones capable of operating at high working frequencies (even of the order of hundreds of kilohertz), and with the consequent increase in the costs associated to the use of these components.
This disadvantage is particularly felt in the automotive sector, where, as is known, the production costs play a frequently determining role in the design choices.